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61.
Hien P. Z. Mai T. K. Quang T. X. Thuy T. N. 《Journal of Radioanalytical and Nuclear Chemistry》1986,105(6):351-355
The ko, Au-factors of 10 elements have been determined by irradating the samples with thermal neutrons in the reactor thermal column. The proposed method has the advantage of eliminating the errors induced by the uncertainties of the neutron spectrum parameters and the nuclear data. The results obtained are in good agreement with the literature data. 相似文献
62.
Ishibashi Chiaki Ichiyama Mai Ishida Naoya Kitamura Naoto Idemoto Yasushi 《Journal of Solid State Electrochemistry》2022,26(3):663-682
Journal of Solid State Electrochemistry - The stable structures associated with the second charge of MgCo2−xMnxO4 (x = 0, 0.5), where Mg is removed from the stable first-discharge... 相似文献
63.
Chromatographia - The present work deals with the optimization, validation and application of a versatile HPLC–DAD method for concurrent estimation of nine antimicrobials and proton pump... 相似文献
64.
Comparative Study of CuO Species on CuO/Al2O3, CuO/CeO-Al2O3 andCuO/La2O-Al2O3 Catalysts for CO Oxidation 下载免费PDF全文
CuO/Al2O3, CuO/CeO2-Al2O3, and CuO/La2O3-Al2O3 (denoted as Cu/Al, Cu/CeAl, and Cu/LaAl) catalysts were prepared by an impregnation method. CuO species and CuO/Al2O3 thermal solid-solid interaction were characterized by in situ XRD, Raman spectroscopy and H2-TPR techniques. For the Cu/Al catalyst, a CuAl2O4 phase exists between the CuO and Al2O3 layer and the CuO phase exists on the surface in both highly dispersed and bulk forms. For the Cu/CeAl catalyst, there is highly dispersed and bulk CuO on the surface, but most of the CuO has transferred into the internal layer of CeO2 as bulk CuO and CuAl2O4. For the Cu/LaAl catalyst, only bulk CuO is present on the surface of the catalyst and no CuAl2O4 is formed. The catalytic activity order for CO oxidation is Cu/CeAl>Cu/Al>Cu/LaAl. The highly dispersed CuO on the catalyst surface may be the active phase for CO oxidation. The results show that the addition of CeO2 not only promotes both the transference of CuO and the formation of CuAl2O4 but also favors the CO oxidation due to the association of highly dispersed CuO with CeO2, while La2O3 hinders the transference of CuO and the formation of CuAl2O4. 相似文献
65.
66.
Jonathan S. Dordick K. C. Backman R. Balakrishnan R. Brent M. S. Ptashne L. P. Casson S. A. Goff A. L. Goldberg P. A. Cornelius R. M. Hochstrasser N. R. Kallenbach H. Rubin G. J. Todaro H. A. De Boer J. C. Delgoffe M. Lobmann N. ZyGraich L. Gehrke T. Kunkel A. Paau S. G. Platt L. Sequeira M. A. Palladino H. G. Roman D. Hultmark T. T. Rasmusan H. Steiner 《Applied biochemistry and biotechnology》1990,26(1):107-113
Protein engineering and site-directed mutagenesis is becoming immensely important in both fundamental studies and commercial applications involving proteins and enzymes in biocatalysis. Protein engineering has become a powerful tool to help biochemists and molecular enzymologists elucidate structure-function relationships in enzymic active sites, to understand the intricacies of protein folding and denaturation, and to alter the selectivity of enzymatic catalysis. Commercial applications of engineered enzymes are being developed to increase protein stability, widen or narrow substrate specificity, and to develop novel approaches for use of enzymes in organic synthesis, drug design, and clinical applications. In addition to protein engineering, novel expression systems have been designed to prepare large quantities of genetically engineered proteins. Recent US patents and scientific literature on protein engineering, site-directed mutagenesis, and protein expression systems related to protein engineering are surveyed. Patent abstracts are summarized individually and a list of literature references are given. 相似文献
67.
68.
采用薄膜分散法合成磷脂微囊,根据胶粒的双电层理论,通过在微囊中加入氯化锰、氯化钙和氯化镁电解质溶液,使微囊处于相对稳定的状态.研究发现加入氯化锰和氯化钙溶液,微囊胶体的粒径没有明显的变化,但加入一定浓度氯化镁溶液,其粒径明显变大.为了进一步增加磷脂微囊稳定性,将氯化锰、氯化钙、氯化镁磷脂微囊胶体分别与海藻酸钠(SA)溶液混合.结果表明,氯化镁与SA几乎不能形成水凝胶,氯化钙与SA形成水凝胶能力强于氯化锰.微囊胶体溶液中的磷脂酰丝氨酸(PS)可以与Ca~(2+)和Mg~(2+)键合形成PS-Ca~(2+)和PS-Mg~(2+),但不能与Mn~(2+)键合形成PS-Mn~(2+).对氯化钙磷脂微囊与海藻酸钠合成的复合水凝胶的形貌、溶胀率及细胞毒性进行了表征,结果表明,氯化钙与SA形成的水凝胶可以捕获胶体中磷脂微囊,且形貌规整,结构稳定,无细胞毒性. 相似文献
69.
Phu H. Dang Tho H. Le Phuong K.T. Phan Phuong T.T. Le Mai T.T. Nguyen Nhan T. Nguyen 《Tetrahedron letters》2017,58(16):1553-1557
Two acridones, paratrimerins C (1) and D (2), and two coumarins, paratrimerins E (3) and F (4), were isolated from the CHCl3 and EtOAc extracts of Paramignya trimera (Rutaceae), together with twelve known compounds (5–16). Their structures were elucidated on the basis of spectroscopic data. All isolated compounds possessed significant α-glucosidase inhibitory activity in a concentration-dependent manner, and showed more potent inhibitory activity, with IC50 values ranging from 14.6 to 112.2 μM, than the positive control acarbose (IC50, 214.5 μM). The biosynthesis of the isolated coumarins and acridones was proposed. 相似文献
70.
Mai Kuroha Hikaru Hemmi Mayumi Ohnishi-Kameyama Shinya Kodani 《Tetrahedron letters》2017,58(35):3429-3432
A new lasso peptide named subterisin was isolated from the culture broth of Sphingomonas subterranea NBRC 16086T. The molecular formula of subterisin was established as C78H121O22N21 based on accurate mass analysis. The chemical structure of subterisin was determined by 2D NMR experiments. The presence of macrolactam ring of Gly1–Glu8 was indicated by NOESY experiment and MS/MS analysis. The three-dimensional structure of subterisin in solution was established by calculation based on NMR data. The proposed biosynthetic gene cluster of subterisin was found on the genome of S. subterranea. 相似文献